Support for Study Design, Database Design and Management, Statistical Analysis Assistance Study Design 1. Advice and support in study design, including evaluating feasibility and validity of proposed designs. 3. Sample size calculations for statistical power and precision. 4. Advice and support concerning the development of the appropriate data collection tools. 5. Educating Center users, and their trainees, about the appropriate methods for the design of studies. 6. Support in design of new research proposals. Database design and management 1. Determining project database hardware and software requirements and data flow. 2. Interacting with user and biostatistician on database definition to facilitate statistical analysis. 3. Consulting on input forms design, data flow, data entry, validation, and reporting of data. 4. Designing, testing, and implementing database structures and application programs. 5. Training Center members in use of hardware and software. Statistical Analysis Assistance 1. Providing consultation on selection of statistical methods for data analysis. 2. Performing both exploratory and inferential data analyses. 3. Collaborating with users in dissemination of results through support in abstract and manuscript preparation. 4. Developing new statistical methodology. 5. Educating Center members and their trainees about the statistical methods for data analysis.